Method for drilling well bores



F. L. LE BUS, SR

METHOD FOR DRILLING WELL BORES I April 10, 1962 3 Sheets-Sheet 1 Original Filed Jan. 14, 1955 &

INVENTOR. FL. Le Bu$,5n

ATTORNEY April 10, 1962 F. LE BUS, SR

METHOD FOR DRILLING WELL BORES 3 Sheets-Sheet 2 Original Filed Jan. 14, 1955 mmvm. F L. LeBus. 5/:

ATTORNEY A ril 10, 1962 F. LE'BUS, sR 3,028,921

METHOD FOR DRILLING WELL BORES Original Filed Jan. 14, 1955 3 Sheets-Sheet 3 INVENTOR.

I 9 BY FL. Le Bus, 5/:

rrow/5y United States doc 3 Claims. (Cl. 17 557) This invention relates to improvements in the method of rotary drilling of Well bores, and more particularly, but not by way of limitation, to a novel method for drilling an oil or gas well bore with the utilization of a combined slip and safety joint for a rotary drilling string. This application is a divisional application of applicants co-pendng application Serial No. 481,755, filed January 14, 1955, and entitled Slip Joints now Patent No. 2,886,289.

In the usual method of rotary drilling of oil Wells, particularly deep bores, the drill bit is secured on the lower end of a drilling string which is rotated at the surface of the well through the drilling rig which includes a rotary table and cooperating kelly therewith. The kelly is usually a square shaped elongated member disposed in an aperture in the rotary table for movement downwardly therethrough. As the drill string proceeds downwardly, it is necessary to periodically add extra joints of drill pipe for making additional depth into the well bore. When this is necessary, the kelly is usually moved upwardly above the apertured rotary table, and the additional joint of pipe is inserted between the kelly and a previous top section of the drill pipe, whereupon the drilling string is again lowered to begin the drilling operation. In the present method of drilling a well, and with the presently available equipment for inserting an additional joint of pipe, it is usually necessary to'raise the drill bit, or core bit from the bottom of the well an equal distance that the drill string is raised so that the extra section or joint of pipe may be added'to the string.

As greater oil reserves are being sought, wells are being drilled to increasingly greater depths with resulting greater hazards and expenses. For this reason, a driller desires the greatest amount of information available relating to the sub-surface formations encountered in a well bore. The usual method of obtaining the desired data is the well known procedure of coring the formation. The core barrel, which is normally used to drill through the formation, drills over a small diameter section of the formation and retains a solid unit thereof within the core barrel. This solid unit or core sample is mechanically recovered and brought to the surface of the well for careful analysis. The drilling of a well to a depth of ten thousand feet or over with a core barrel on the bottom of the drill pipe is a costly project, and for this reason it is desired to obtain maximum results with the core barrel. As a result, the use of diamond studded core bits has become generally accepted in the industry. These diamond bits are quite expensive, and every elfort is made to prolong their useful life.

Most wells are drilled by a method utilizing a well known drilling tool called a rock bit which rotates on the bottom of the bore hole. These rock bits are provided with hardened teeth to grind up the formatiomand during the drilling of hard formations, such as granite and chert, many of the hard teeth are often broken olf and will float in the circulating mud around the drill pipe with the small pellets of broken formation. In this condition, the pellets do not do any particular damage or interfere with the drilling or coring operation of the rig. When the bit is raised off the bottom of the well as heretofore mentioned, however, these floating hazards settle down into the bore hole, and when the bit is lowered to continue the drilling trapped under the cutting surface of the bit. When rotation of the bit is continued, the broken off hardened portions under the drill or core bit will start a rolling action that causes considerable damage to the bit, particularly the expensive diamond core bit, so that in a very short.

time it becomes practically useless.

This invention is generally concerned with a novel method of drilling a well bore in order to utilize an improved slip joint for a drilling string when it is necessary to add additional sections of pipe to the drill string for a continued drilling operation, and particularly to a method utilizing a slip joint that will permit insertion of the additional section of drill pipe without lifting the drilling bit or core bit off the bottom of the well bore. It is also well known in rotary drilling that telescopic sections have been used in the drill strings in order to limit the weight applied to the drill bit so that drilling or coring bits would not-be subjected to enormous weights of the entire drill stem causing a faster drilling, or crushing of the drill bits, and if proper braking power was not applied would have a tendency to cause crooked hole drilling. This invention also provides a method of drilling which permits substantially any pre-determined weight or variation of weight that may be desired by the driller to enable the bit head to penetrate the formation being drilled at a smooth, efiicient speed of penetration. This is particularly desirable when drilling in deep bores with long and heavy strings of drill pipe. The driller will usually vary the weight of the drill string acting upon the drill bit by utilization of the braking apparatus at the surface of the well, but this practice is subject to the normal inaccuracy of the human element. With predetermined knowledge of the weight of the core barrel, the desired number of drill collars and a partial section of the slip joint, the necessary weight for an eflicient and regulated penetration may be readily calculated and maintained. It is an important object of this invention toprovide 8. improved method for drilling well bores which provides for the addition of extra sections of pipe in the drilling string without lifting the drilling bit from the bottom of the well bore.

And still another object of this invention is to provide a method of drilling well bores with a slip joint cooperating with the drilling string in such a manner that the weight of all elements of the drilling string below the slip joint and including part of the slip joint may be easily pro-determined and calculated in order to make up the necessary weight required for the drill bit to penetrate the formation in a more efficient and regulated speed of penetration into the formation being drilled.

And still another object of this invention is to provide an improved method of drilling a well bore with a novel slip joint which will permit insertion of an additional joint of drill pipe without removal of the drill bit from the well bore, and yet permit operation of the drill bit when the slip joint is in an expanded open position.

And still another object of this invention is to provide 1 an improved method for drilling well bores in such a manner as to permit any variation in weight as required in any drilling operation to penetrate formations being drilled in an emcient manner.

And still'another object of this invention is to provide an improved method of well drilling with a novel slip joint which will permit a hydrostatic head to build up therein, thus precluding the possibility of collapse of the unit during high pressure conditions caused by drilling depths.

And still another object of this invention is to provide a novel method for drilling well bores which is simple practical and economical in practice.

Other objects and advantages of the invention will be evident from the following detailed description, read in conjunction with the accompanying drawings, which illustrate my invention.

In the drawings:

FIGURE 1 is a broken vertical sectional elevational view with certain parts in elevation for clarity depicting the upper portion of the novel slip joint.

FIGURE 1A is a view similar to FIG. 1 of the lower portion of the novel slip joint interposed in a drill string at the beginning of a drilling operation.

FIGURE 2 is an enlarged detail view inperspective of the cooperating spline members of the slip joint.

FIGURE 3 is a view taken on line 3--3 of FIG. 1.

FIGURE 4 is a view similar to PEG. 1 showing the upper portion of the slip joint with the control spline in a position to provide for a lesser weight on the drill bit.

FIGURE 5 is a view similar to FEG. 4 showing the upper portion of the slip joint with the control spline moving slightly off or in a parting direction during expanding operation of the telescopic procedure.

FIGURE 6 is a view taken on line 6-6 of FIG. 4.

FIGURE 7 is a view taken on line 77 of FIG. 4.

FIGURE 8 is a view taken on line SS of FIG. 5.

FIGURE 9 is a view similar to FIG. 1 of the upper portion of the slip joint showing a separated position of the control spline when it is necessary to add an additional joint of pipe.

FIGURE 10 is a perspective view of one side of the control grooves.

FIGURE 11 is a view similar to FIG. 10 showing the opposite side of the control groove.

FIGURE 12 is a broken elevational view with certain parts in section of the lower portion of a drill string and depicting the drill bit in a raised position from the bottom of the bore hole.

Referring to the drawings in detail, and particularly FIGS. 1 and 1A, reference character 5 indicates generally a slip joint adapted to be interposed in a drill string 6 in a well bore 7, the bottom of which is indicated in FIGS. 1A and 12. A rotary kelly member (not shown) cooperates with a rotary table (notshown) normally utilized with a drilling rig (not shown) at the surface of the well. The rotary table connects with the top string of drill pipe (not shown) which extends into the well bore for connection at 9 with the upper sub member 11. The sub member 11 is connected through complementary threads 13 with a downwardly extending cylindrical housing 15 in turn cooperating with a clutch member 17 connected at 18 with an intermediate cylindrical housing 19 to provide structural housings for the slip joint 5. The sleeve 19 is connected by complementary threads 20 to a lower sub member 21 in turn connected to the drill section 6 having a core barrel 22 and any suitable type of core drill 24 disposed at the lower end thereof for drilling the bottom 26 of the well bore 7. A suitable safety joint 8 is interposed between the drill string 6 and the barrel 22 to permit removal of the complete core when the outer barrel is stuck, and is the usual practice in the industry.

The sleeve member 15 is provided with aplurality of circumferentially spaced male spline or clutch lug-members 30 integral with the inner periphery of the sleeve 15, and preferably comprises two diametrically spaced lugs 30 :around the circumference, but not limited thereto. It will be understood that any practical number of lugs 30 may be utilized as desired. The apertured member 17 is provided with an upstanding reduced neck portion, or sleeve 32 having a plurality of circumferentially spaced longitudinal grooves 34. The grooves are female splines cooperating with the male splines 30 for a purpose as will be hereinafter set forth. The sleeve 32 is further provided with a plurality of circumferentially spaced longitudinal grooves 36 spaced from the top 38 of the sleeve 32 and extending upwardly from a horizontal a recess 40 in communication with the groove 34. The groove 36 is provided with a shoulder 42 at its uppermost end and a pair of longitudinal shoulders 43 and 45 for a purpose as will hereinafter be set forth. The female splines 34 are provided witha tapered portion 44 to facilitate association of the lugs 36 with the groove 34.

A shouldered portion 48 on the sleeve 17 as is clearly shown in FIGS. 1 and 2 is provided with a recessed portion 50 in which is disposed a latch member 52 supported by a helical spring 54 anchored in the bottom of the recess 59. A cover plate 55 is suitably secured to the sleeve 17 to maintain the latch 52 and spring 54 within the recess 56. The helical spring 54 urges the latch member 52 upwardly into communication with a plurality of complementary notches or teeth 56 provided in the lower rim 58 of the sleeve member 15. A plurality of circumferentially spaced latch members 52, preferably two, but not limited thereto, cooperate between the rim 58 and the shouldered portion 48 to maintain a locking engagement between the sleeve 15 andthe sleeve 17 in a manner as will be hereinafter set forth.

The splined portions 30 and 34 provide for a telescoping arrangement of the slip joint, but the lugs 30 are clutch locked in recess 36 to prevent any unt 'arranted telescopic disposition during a lowering of the slip joint into the bore. The spring urged latch members 52 cooperate with the teeth 56 to preclude accidental left hand rotation of the sleeve 15 with respect to the member 17 during the lowering operation. If the lugs 36should accidentally turn out of the groove 36 and enterthe slot 34 while the slip joint 5 is being lowered into the well here, the combined weight of the drill collars 6, safety joint 8, core barrel 22 and bit 24 may cause these connected sections to drop within the well and causeinoperable damage.

The sub member 11 has a threaded aperture 60 in alignment with a centrally disposed longitudinal aperture (not shown) in the sleeve 32 and the member 17. A circulating and telescoping stem 62 extends through the apertures and is connected at 60 to the sub 11 and extends downwardly through the bores to a point slightly above the sub 21. The lower end of the stem 62 is provided with a slot or groove 64 (FIG. 1A) adapted to cooperate with a suitable tool (not shown) for tightening and loosening of the stem 62 therein. An outwardly extending shoulder 65 is provided on the outer periphery of the stem 62 and is spaced slightly above the slot 64 for receiving a substantially cup shaped packer 66, preferably made of rubber, or the like, but not limited thereto. A thimble shaped seat 68 is disposed adjacent the top of the packer 66 and supports a spacer bushing 70. A second packer 72, similar to the packer 66, is disposed atop the spacer 70 and supports a pair of thimble seats 73 and 74. An inverted packer 75 rests in the seat 74 and is adapted to receive a spacer bushing 76 similar to the spacer 70. A clutch member 78 is disposed immediately above the plurality of packers and is adapted tocooperate with a complementary clutch member provided on the lower end of: the clutch member 17 (FIGS. 1, 4 and 9). The body of the member 78 provides a solid piston portion 79 for a purpose as will be hereinafter'set forth. The sleeve 19 is provided with a plurality of circumferentially disposed apertures 82 disposed substantially adjacent the clutch member 80 for a purpose as will hereinafter be set forth.

Prior to disposition of the slip joint unit 5 in the well bore, manual pressure isexerted on the top of the sleeve 15'to force it downward against the'shoulder 48, thereby pressing the latch members 52 downward against the action of the spring 54. In this downward position the splines 30 are at the bottom of the grooves 34 and a clockwise or right hand movement will place the splines 30 into communication with the grooves 36. As hereinbefore stated, the latch members 52 cooperating with the teeth 56 will prevent accidental left hand movement of the sleeve 15 with respect to the sleeve 17. In this 2) manner, there, will be no disengagement of the slip joint 5 while it is being lowered into the well bore.

A suitable thrust bearing 84 is disposed around the upper portion of the stem 62 and is interposed between the upper sub 11 and the upwardly extending sleeve 32 of the member 17 for a purpose as will hereinafter be set forth.

Operation In assembly, a continued right hand rotation of the drill stem drives the complete assembly downwardly, and as the bit 26 penetrates the format-ion the splines or groove 36 will drive off or move vertically downward relative to the male lugs 30. It will be noted that the male lugs 31 and the grooves 36 have a limited length of drive contact, approximately two feet, but not limited thereto. This is necessary so that the operator will have to-feed the rotary kelly (not shown) downward after approximately two feet of cored hole in the bore 7 has been made. A continuous feed of the kelly must be made as the core bit penetrates the formation further. From the pre-determined weight calculation, the speed of penetration is regulatedto the speed of drilling and the operator will have to lower the kelly at approximately the same rate as the core bit 24 penetrates the formation to prevent the lugs 30 from engaging the shoulder 42 and reducing the weight on the bit. Because the clutch members are shorter than the ordinary kelly, it will continually feed after a certain normal penetration has been made in order to add additional sections of drill pipe without raising the drill, or core bit, off the bottom of the well bore. In practicing the drilling method, it is desirable not to raise the core bit, so that pellets, rocks, and the like, cannot fall under the bit before lowering it back to the bottom, as clearly indicated inFIG. 12. Consequently, the operator must lower the kelly at approximately the same rate of speed as the core head penetrates the formation and as soon as the kelly approaches the bottom of its feed, then it is desirable to add an extra joint of pipe to continue the drilling operation. The method of operation of the slip joint is then as follows, and shown in FIG. 9.

When it is desired to add an extra joint of pipe to continue the drilling operation, pressure is exerted on the top of sleeve to force it downward against the shoulder 48 and the sleeve 15 is rotated counterclockwise with sufficient force to overcome the spring urged latch 52 so that the lug 30 is moved out of the groove 38 and into communication with the groove 34. In this position, the lugs are moved vertically upward to assure disengagement with the grooves 34 with a simultaneous movement of the stem 62 upwardly bringing the clutch members 73 in contact with the clutch dogs 86 In this upward movement, it will be apparent that the drill bit 24 is not moved, but remains stationary on the bottom 26 of the well bore 7, thus assuring that no rocks, boulders, pellets of cheit, or the like, will fall into the bore 7 beneath the bit 24 and cause costly damage to the core bit upon resumption of the drilling operation. It is not necessary that the clutch dogs 78 and 80 be in connected relation, but may be so as shown in FIG. 9 when it is desired to rotate the drill string for any purpose as may be desired, such as a slightly stuck bit, or the like.

Upon the adding of a section of drill pipe, the lug 30 is again placed in a drive position within the slot 36, and it will be apparent that right hand rotation of the sleeve 15 will bring the lug 39 into contact with the longitudinal shoulder 43 to communicate the rotative movement to the drill sections therebelow, thus permitting a smooth penetration into the formation. Similarly, a left hand rotation will bring the lug 36 into contact with the shoulder 45 to communicate the rotative motion to the lower sections, thereby permitting a backing oif, or the like, in the bore 7 if desired with no possibility of disengagement of the lugs 39 from the sleeve section 17. The teeth 56 perform a dual function. Not only do they cooperate with the latches 52 as hereinbefore described, but also they mation loosens up, such as in a sand or shallow format-.-

barrel, drill bit and safety joint below the slip joint can be utilized to an advantage by a driller according to the variations of the formation. In utilizing this pre-determined weight in a particular formation, a slight braking at the surface of the Well will maintain the male splines 30 in a neutral spaced relation between the shoulders 42 and 48 when in a drive position. However, as the fortion, the weight may be decreased at the surface of the well permitting the lug 38 to hang on the upper shoulder 42 so that the driller may vary the weight according to the density of the formation. Of course, as the formation increases in density or hardness, and additional weight is required, the braking apparatus at the top of the Well is utilized to increase the weight and cause the male spline 34 to be moved downwardly to a position slightly above the lower shoulder 48, thereby adding additional weight over the pro-determined weight as is desired.

The apertures 82 are provided to receive circulating drilling fluid normally utilized during the drilling operation of the tool for the removal of cuttings. It will be apparent that an upward movement of the piston portion '79 of the clutch dog 78 will displace any fluid that passes through aperture 82 into the interior of housing 19. The tubular stem 62 provides for fluid circulation longitudinally through the entire unit so that fluid may be circulated from the drilling unit into the annulus between the drill collars and the well bore. The packing glands 66, 72 and 75 (FIG. 1A) prevent fluid from circulating back into the unit and also prevent fluid that has discharged through the apertures 82 from leaking below the packing glands, thus preventing the circulation fluid from backing into the unit. Thus, sutficient lubrication to the bit 24 is assured. The discharge of fluid from the annular space 86 between the well bore and the drill collars through the apertures 82 will effect a hydrostatic head within the chamber 87 of the housing 19 to assist in preventing pipe collapse under conditions of extreme pressures caused by increased well depths. It will be apparent that the unit 5 provides for fluid circulation downwardly through the annular space 86 between the drill collar and the well bore and upward through the stem 62 or vice versa.

From the foregoing, it will be apparent that the present invention contemplates an improved method of drilling well bores with a slip joint assembly which permits the insertion of an additional section of pipe in the drill string without removal of the drill bit off the bottom of the well bore. It will be apparent that this novel method is accomplished through the use of a telescopic type of slip joint having a clutch apparatus of male and female splines of limited length, thereby necessitating a continuous feed of the rotating kelly of the drill string to provide for variation in the desired weight which is communicated to the drill bit for penetration of formations of variable densities. Furthermore, the method contemplates a pre-determined weight which may be easily calculated to assure speed of rotation for the drill string complementary to the speed of penetration of the drill bit to assure that there is an efficient feeding of the kelly relative to the clutch splines and there will be a limited drilling off because shoulder 42, by virtue of its contact with the upper end of clutch 30, prevents the deeper penetration of the drill bit and core barrel and drill collars, unless there is a feeding off of weight at the kelly joint. In addition, the slip joint assembly is locked during lowering of the drill string into the well bore to prevent telescopic spreading thereof. The locking means are assisted by a latching member for maintaining the slip joint in assembly condition. The invention also contemplates a novel arrangement for providing a hydrostatic head of circulating drilling fluid within the slip joint unit to prevent pipe collapse at extreme pressures,

7 yet sealing the drilling fiuid from the operating clutch mechanism of the unit.

Changes may be made in the combination and arrangement of parts as heretofore set forth in the specification and shown in the drawings, it being understood that any modification in the precise embodiment of the invention may be made within the scope of the following claims Without departing from the spirit of the invention.

I claim:

1. The method of drilling a well bore by means of a rotary kelly and a drill string having a bit thereon and a telescopic drill joint interposed therein having latching means for locking thereof in a collapsed position, and which consists of latching the telescopic drill joint for maintaining the telescopic drill joint in the collapsed position during lowering of the bit and drill string in the well bore, rotating the drill string having the telescopic drill joint interposed therein in a right hand direction for penetration of the well bore, maintaining a continuous downward feeding of the kelly at substantially the same rate of speed as the bit penetration rate to maintain the telescopic dn'll joint slightly extended to provide continuous penetration of the bit in the well bore, maintaining a predetermined weight on the bit by utilizing the weight of the portion of the drill string below the telescopic drill joint for controlling the speed of penetration thereof in the well bore, interrupting the penetration operation for lengthening the drill string by rotating the drill string in a left hand direction for releasing the latching engagement to permit a partial disconnection at the telescopic drill joint, subsequently extending the telescopic drill joint by raising the upper portion of the drill string in the well bore to provide a limited separation of the drill string, inserting additional pipe sections in the drill string, maintaining the bit on the bottom of the well bore during the addition of the pipe sections in the drill string, lowering the lengthened drill string into the well bore, connecting the upper portion of the separated drill string with the bit by contraction of the telescopic drill joint, and rotating the drill string in a right hand direction for continuing the drilling operation.

2. The method of drilling a well bore by means of a rotary kelly and a drill string having a bit thereon and a telescopic drill joint interposed in the drill string having latching means for locking the telescopic drill joint in a collapsed position, and which consists of latching the telescopic drill joint in the collapsed position during lowering of the drill string and bit into the well bore, rotating the drill string in a right hand direction for penetration of the well bore, maintaining a continuous downward feeding of the kelly at substantially the same rate of speed as the bit penetration to maintain the telescopic drill joint slightly extended to provide continuous penetration of the bit in the well bore, maintaining a pre-determincd weight on the bit for controlling the speed of penetration thereof the lower portion thereof at the drill joint, preeluding a complete disconnection between the upper and lower portions of the drill string, raising the upper portion of the drill string in the well bore for the insertion of additional pipe sections therein, maintaining the bit on the bottom of the well bore during the addition of the pipe sections in the drill string, lowering the lengthened drill string into the well bore, connecting the upper portion of the drill string with the bit, and rotating the drill string in a right hand direction for continuing the drilling operation.

3. The method of drilling a well bore by means of a rotary kelly and a drill string having a bit thereon and a telescopic drill joint interposed therein having latching means for locking thereof in a collapsed position, engaging the latching means of the telescopic drill joint, maintaining the telescopic joint locked in the collapsed position during lowering of the bit and drill string in the well here, rotating the drill string having the telescopic drill joint interposed therein in a right hand direction for penetration of the well bore, maintaining a continuous downward feeding of the kelly at substantially the same rate of speed as the bit penetration rate to maintain the telescopic drill joint slightly extended to provide continuous penetration of the bit in the well bore, maintaining a predetermined weight on the bit for controlling the speed of penetration thereof in the well bore by utilization of the weight of the portion of the drill string below the telescopic joint, interrupting the penetration operation for lengthening the drill string by rotating the drill string in a left hand direction for releasing the latching engagement of the telescopic drill joint to permit a disconnection of the upper portion thereof from the lower portion thereof at the telescopic drill joint, precluding a complete discon nection between the upper and lower portions of the drill string, extending the telescopic drill joint by raising the upper portion of the drill string in the well bore for a partial removal therefrom, inserting additional pipe sections in the drill string, maintaining the bit on the bottom of the well bore during the addition of the pipe sections in the drill string, lowering the lengthened drill string within the well bore for contracting the telescopic drill joint, connecting the upper portion of the separated drill string with the bit by contraction of the telescopic drill joint, rotating the drill string in a right hand direction for continuing the drilling operation, providing fluid circulation through the drill string, and maintaining a hydrostatic pressure head in the drill pipe for precluding collapse thereof under well bore pressures.

References Cited in the file of this patent UNITED STATES PATENTS 541,171 Le Grand June 8, 1895 1,905,497 Peters n Apr. 25, 1933 2,049,290 Burns July 28, 1936 2,500,276 Church Mar. 14, 1950 2,572,895 Waggener Oct. 30, 1950 2,585,995 Brown Feb. 19, 1952 2,606,003 McNeill Aug. 5, 1952 2,624,549 Wallace Jan. 6, 1953 2,684,835 Moore July 27, 1954 2,776,817 Gregory et al Jan. 8, 1957 

